module.exports = app => {
    const {STRING, INTEGER} = app.Sequelize;

    const Chapter = app.model.define('chapter', {
        title: STRING,
        orderby: INTEGER,
    })
    Chapter.associate = function(){
        app.model.Chapter.belongsTo(app.model.Book, {
            foreignKey: 'book_id',
            as: 'book'
        })

    }
    return Chapter;
}